1. Technical Field
The present invention relates to an image capture system for recording X-ray images in real time. More particularly, it relates to an image capture system for recording X-ray images in real time and is applicable to a surgical navigation system.
2. Description of Related Art
Conventionally, prior to orthopaedic surgery, medical imaging instruments, such as CT (Computed Tomography) scanners, MRI (Magnetic Resonance Imaging) devices, etc., are used to capture images of patients' nidi for giving doctors more information about the locations and sizes of nidi. Consequently, doctors can plan incision locations, directions, depths, and the like according the images. However, even by reading such images, the doctors have to conjecture nidus locations with their knowledge of the anatomy or from their clinical experience. Accurate pre-surgery planning is difficult to accomplish in practice, especially in cases where the nidi is nestled deep inside the body. As a result, doctors are put in the predicament where they are forced to cut through layers of tissue, blindly seeking for the nidi.
For eliminating such predicaments, a doctor may implement a surgical navigation system to obtain pictures of nidi before surgical operation and employ image analysis software to reconstruct the pictures into three-dimensional images. Then the three-dimensional images can be read and accurate pre-surgery planning can be achieved by using the same so as to render subsequent surgery less difficult and more successful. However, in addition to clear, high-definition images, accurate pre-surgery planning and smooth surgical operation also require highly precise information about the relative position between the images and the patient's actual nidus.
Generally speaking, for such a surgical navigation system to precisely guide a surgical instrument to a nidus during operation, position marks may be provided to an X-ray machine and the nidus so that after X-ray images of the patient's nidus are taken, the surgical navigation system can show the relative position between the X-ray machine and the patient's nidus, thereby obtaining image coordinates of the nidus.
FIG. 1A is a schematic drawing showing usage of a conventional surgical navigation device 10 and an X-ray machine 11 while FIG. 1B is another schematic drawing of the surgical navigation device 10 and the X-ray machine 11.
As shown in FIG. 1A, a typical surgical navigation device 10 uses an image capture device therein to obtain X-ray images from a display device of the X-ray machine 11 or from the X-ray machine 11 itself. A position device 12 in the surgical navigation device 10 records the relative relation between the X-ray images (i.e. the position of the X-ray machine 11) and a nidus. However, since the X-ray machine 11 commonly implemented in hospitals is not linked to the surgical navigation device 10, and a shutter button of the X-ray machine 11 and an image-taking switch of the surgical navigation device 10 are provided separately at the two individual apparatuses. During operation, an operator has to first trigger the shutter button of the X-ray machine 11 in order to take the X-ray images, turn on the image-taking switch of the surgical navigation device 10 to acquire the X-ray images, and finally, actuate the position device 12 of the surgical navigation device 10 so as to derive the relative position between the X-ray machine 11 and the nidus.
Nevertheless, as shown in FIG. 1B, after the X-ray images are taken, once the patient unintentionally moves and causes change in the relative position between the nidus and the X-ray machine 11, the relative relation between the X-ray machine 11 and the nidus determined by the surgical navigation device 10 becomes untrue. As a result, the surgical navigation device 10 may erroneously guide the surgical instrument and thus the accuracy of the surgical navigation is compromised.